This study represents an extension of our original project to evaluate flow microfluorometry (FMF) as a rapid and quantitative method for diagnosis, classificaton and monitoring of human lymphomas and leukemias. We have already shown that by FMF analysis, nearly 90% of Hodgkin's lymphomas can be distinguished from non-neoplastic tissues. Furthermore, preliminary clinical studies in lymphomas have demonstrated an excellent correlation between the percentage of cells in the S phase of the cell cycle as determined by FMF and the clinical course of the disease. These studies indicate that FMF may become an objective method in the diagnosis and classification of human lymphoid neoplasms, potentially more accurate than conventional morphology. In the present study, we will extend these observations to a larger number of patients with malignant lymphoid disease. We will emphasize the quantitation of S cells and the detection of abnormal cellular DNA content and light scatter emissions both singly and by simultaneous correlated analysis. The study of human B cell lymphomas by fluorescent beads coated with anti-light chain or anti-idiotypic antibodies to label selectively neoplastic B cells will allow the analysis of cellular DNA of malignant and non-malignant subpopulations obtained from the same sample. Response to therapy will be correlated with changes in the FMF histograms of the neoplastic samples obtained by needle aspirate or biopsy prior to and following administration of anti-neoplastic therapy. The late effects of anti-neoplastic therapy on DNA content in normal cells will be studied in lymphocytes of treated non-leukemic patients who are currently in remission.